Biko M. Gadaga Division of Veterinary Technical Services D&R Branch, Central Veterinary Labs

1. Review of Newcastle Disease control in backyard poultry with emphasis in vaccination campaign evaluation Biko M. Gadaga Division of Veterinary Technical Services D&R Branch, Central Veterinary Labs Box CY551, Causeway, Harare bikogadaga@yahoo.com

2. Opening remark “Man, despite his artistic pretensions, his sophistication and many accomplishments, owes the fact of his existence to a six-inch layer of topsoil and the fact that it rains.” Anonymous

3. Role of backyard poultry *55% of SHF own cattle, over 70% shoats & 80% chickens which play a complementary role to cattle incl.: • Health& well being – protein source and contain all essential AA , vitamins&minerals. Eggs provide approx. 11.5 %of daily protein & 5% of daily energy requirements, liquidation for grain, high quality manure for veg. gardens • Gender biased- up to 60% women& children own & care • Education- disposal for fees, books & incidentals • Environ. Impact- minimum as they are scavengers * Up to 1/3 of Zims poultry pop. Sector 3&4 (village type/backyard/low biosecurity) note: Av. for Africa + 70%

4. Importance of Newcastle Disease *ND is the most important disease of poultry in Africa & Zimbabwe • As it has potential to wipe out entire flocks • 70-80% of annual losses are due to ND • Control could result in a 42% increase in production • Potential to incr. HH income by 80%. But this is further complicated by: • In ND endemic areas, the disease is generally well-recognised by farmers & this discourages them from investing time & money in improving the standard of their poultry husbandry • Resource poor people least likely to take risks, as a result, adopt new tech only once they are sure of an adequate ROI (time&$) • Dev. partner funded projects have controlled activities which usually lack cont. This lack of sustainability may be due in part to..

5. Overview of ND control The control of ND in the family sector, as in the commercial sector, requires a multifaceted approach. In the commercial sector, ND control consists of (Alexander, 1997): • International control policies – as per OIE standards • National control policies – as per Animal health act • Biosecurity at the farm level - sanitation and security practices • Vaccination

6. Why vaccinate:*Primarily for Disease control *Principle of vaccination : to elicit an immunological response against the virus in a way that does not cause the disease. • Reduce economic losses(egg & meat production) • Hamper diffusion of virulent strains • Tool for disease eradication Types of vaccine: Traditional : Live virus:Hitchner B1, F, La Sota Clone 30, 6/10, VG/GA, V4, I2 Inactivated: Mukteswar New generations Recombinant (FP, HVT) with subunits

7. Current protocol: Sector 3&4 *One/Two rounds of avirulentthermotolerant I2 vaccine sourced from CVL during the dry winter season i.e.- Apr-Jun then Jul-Sep • Note strategic as farmers are not busy in their fields &high incidents of outbreaks occur in winter. Dry season favours movt of chickens to mkt, exchange of animals between villages & regions • Flocks are scattered, multi-aged and usually unhoused • CBV concept allowed the overcoming of extension challenges with realisation of community ownership& op. sustainability • In extensive flocks, economic losses associated with outbreaks are often alleviated by: self-consume, salvage slaughter &sale BUT The same practices enhance the spread of the disease in the area

8. General review (SWOT analysis) Strengths • Community based therefore Relevant, Ownership?,SustainableEffecient. • Local vaccine production therefore cheaper • Competent DVS ext. staff and CBVs Weaknesses • Donor driven, inconsistent labelled & min. ext. staff coop. • Little to NO commercial poultry producer participation • Lacks scientific evaluation tool(effectiveness unknown) • Lacks further farmer education • Poor I2 Vaccine packaging losses, dilution problems

9. General review cont. Opportunities • Improved perception on of role of poultry as a sustainable enterprise to alleviation poverty& major protein source • Backyard poultry is perceived healthier, tastier(Organic) • Advent of Conservation agriculture (CA) &climate change • High grain and oilseed prices • Registration and commercial I2 production Threats • Prioritization of intervention/emergency mitigation in crops • Funding in livestock targeted towards cattle • Ownership gender biased with min. part. of heads of HH • Globalisation , advent of cheap GMO fed imports

10. Review cont. Experience has shown that a sustainable ND control prog. has 4 essential components (Alders et al., 2001): • an appropriate vaccine and vaccine technology; • effective extension materials &methodologies that target veterinary and extension staff as well as CBVs & farmers; • simple evaluation and monitoring systems of both technical and socio-economic indicators; • economic sustainability based on the commercialisation of the vaccine &vaccination services & the marketing of surplus chickens and eggs.

11. Scientific review *Vaccination might be an important tool only if applied adequately&concomitantlywith:adequate bio-security measures& verification sys that detect & eliminate the coz of efficacy reductn • Humoral immunity, Ab against F &HNproteins is of paramount importance for the protection of ND virulent strains • To guarantee vaccination MOST individuals in the vaccinated population should have adequate protection thus transmission of the ND virus might be interrupted only if > 85% shows an Ab titers ≥ 1:8 (Bovenet al., 2008) . • The protection of the “group” of birds in a farm is adequate only if the average Ab titers of the farm is not <1:8 &if at least 75% of the animals have Ab titers not <1:32 (Cameron . 2007)

12. Scientific review cont. The optimal protection is obtained through the use of a live vaccine followed by an inactivated &the ideal interval between two interventions should be of at least 3wks • Whenever Ab titers are considered not protective, it is possible to vaccinate with live vaccines • In a low risk situation, (no circulation of highly pathogenic virus) a minimum vaccination protocol with the predominant use of live vaccines might be adequate. • In a high risk situation and in emergency situation, the use of inactivated vaccines is obligatory to guarantee high Ab titers • Outbreak origin patterns; generally 62% from backyard to backyard system, backyard-commercial 13% &com-com 25% .

13. Vaccine Selection considerations The selection criteria of a ND vaccine for use in backyard poultry: • Ease of use • Thermostability (where cold chain maintenance is a challenge) • Cost • Immunogenicity • Transportability • Availability

14. Recommendations • Continue CBV approach i.e. Recruit & Retrain • Expand ownership to ext& other gvt staff. i.e.- incorporate in workplans wholesome, AI/ND surveillance& vaccination • Commercial producers should take lead as major stakeholder • Repackage I2 vaccine into convenient 200/100 doses • Design scientific M&E tool which inc. social aspects • Conduct further field trials incl. Field strain typing • Inc. other dzz poultry prod. aspects in CBV curriculum • Maintain contacts with international institutions

15. Conclusion Only dead fish follow the flow. • Participatory approach the in thing thus there is need for a consistent program on DVS calendar with/out donor support • CBV concept is sustainable overally and this opportunity needs to be exploited and extended to most disease vaccination and surveillance other than AI and ND. • Instead of limiting to CBV concept there is room to expand it to a Community Based Animal Health worker i.e. a first line to disease management

16. Acknowledgements The Directorate of DVTS in particular Drs Makaya and Nyika for affording me the opportunity to travel to AU/PANVAC and maintaining links with renowned continental and international institutions • Resource personnel at AU/PANVAC particularly Ms Ethel Chitsungo and the team from Padova. • Above all, all present at this LWG presentation.